There were leftover tortillas in my house last week, quickly going stale. There were tomatillos in the market. For a sometime Texan, this means just one thing: chilaquiles.

OK, let me back up.

Tomatillo is a fruit related to tomatoes and cape gooseberries. Photograph by Marisa McClellan

Tomatillos, in case you’ve never encountered them: Small, round things, pale green and firm, and covered with a papery husk. Somewhat like tomatoes, they are botanically a fruit but get used as a vegetable; they have a sweet, acid tang and make superb green sauce.

Chilaquiles: The best thing you can do with leftover corn tortillas, or one of the best, at least. You fry the tortillas until they are crisp (unless you made chips with them, in which case they are crisp to start with); broil the tomatillos, whizz them in a blender and simmer them; fold the tortillas into the sauce and let them soften; and add chicken, if there is any in the fridge. In my house we eat them for brunch, with a runny egg on top, though not often enough.

I was scraping the last smears of sauce from my bowl when it occurred to me that, though I think of chilaquiles as an odd regional one-off—something that makes Southwestern friends hungry and Yankee ones puzzled—they actually belong to a long tradition: recipes that use old bread, or bread’s local equivalent.

Think about it. In Italy, there’s pappa al pomodoro, a chunky soup of tomatoes, oil and stale bread. In Lebanon, fattoush, a salad of chopped tomato, cucumber, dry shards of pita, sometimes greens. In Thailand—most of Asia, in fact—there’s fried rice, made with previously cooked rice, never fresh; and across the same crescent, there’s okayu or congee or jook, rice porridge. In France, pain perdu, what we think of as French toast. In England, bread pudding.